arm64: Add ARCH Timer

SoC sdm845 uses ARCH Timer

Change-Id: I45e2d4d2c16a2cded3df20d393d2b8820050ac80
Signed-off-by: T Michael Turney <mturney@codeaurora.org>
Reviewed-on: https://review.coreboot.org/25612
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

src/arch/arm64/Kconfig

@@ -22,6 +22,10 @@ config ARCH_RAMSTAGE_ARM64
 
 source src/arch/arm64/armv8/Kconfig
 
+config ARM64_USE_ARCH_TIMER
+	bool
+	default n
+
 config ARM64_USE_ARM_TRUSTED_FIRMWARE
 	bool
 	default n

src/arch/arm64/Makefile.inc

@@ -45,6 +45,7 @@ $(call src-to-obj,bootblock,$(dir)/id.S): $(obj)/build.h
 
 bootblock-y += boot.c
 bootblock-y += eabi_compat.c
+bootblock-$(CONFIG_ARM64_USE_ARCH_TIMER) += arch_timer.c
 bootblock-y += transition.c transition_asm.S
 
 bootblock-y += memset.S
@@ -72,6 +73,7 @@ $(objcbfs)/verstage.debug: $$(verstage-objs)
 verstage-y += boot.c
 verstage-y += div0.c
 verstage-y += eabi_compat.c
+verstage-$(CONFIG_ARM64_USE_ARCH_TIMER) += arch_timer.c
 verstage-y += memset.S
 verstage-y += memcpy.S
 verstage-y += memmove.S
@@ -89,6 +91,7 @@ ifeq ($(CONFIG_ARCH_ROMSTAGE_ARM64),y)
 romstage-y += boot.c
 romstage-y += div0.c
 romstage-y += eabi_compat.c
+romstage-$(CONFIG_ARM64_USE_ARCH_TIMER) += arch_timer.c
 romstage-y += memset.S
 romstage-y += memcpy.S
 romstage-y += memmove.S
@@ -115,6 +118,7 @@ ramstage-y += div0.c
 ramstage-y += eabi_compat.c
 ramstage-y += boot.c
 ramstage-y += tables.c
+ramstage-$(CONFIG_ARM64_USE_ARCH_TIMER) += arch_timer.c
 ramstage-y += memset.S
 ramstage-y += memcpy.S
 ramstage-y += memmove.S
@@ -125,6 +129,7 @@ rmodules_arm64-y += memset.S
 rmodules_arm64-y += memcpy.S
 rmodules_arm64-y += memmove.S
 rmodules_arm64-y += eabi_compat.c
+rmodules_arm64-$(CONFIG_ARM64_USE_ARCH_TIMER) += arch_timer.c
 
 ramstage-srcs += $(wildcard src/mainboard/$(MAINBOARDDIR)/mainboard.c)
 

src/arch/arm64/arch_timer.c

@@ -0,0 +1,25 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018, The Linux Foundation.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <timer.h>
+#include <arch/lib_helpers.h>
+
+void timer_monotonic_get(struct mono_time *mt)
+{
+	uint64_t tvalue = raw_read_cntpct_el0();
+	uint32_t tfreq  = raw_read_cntfrq_el0();
+	long usecs = (tvalue * 1000000) / tfreq;
+	mono_time_set_usecs(mt, usecs);
+}

src/arch/arm64/armv8/lib/sysctrl.c

@@ -1059,3 +1059,11 @@ void raw_write_cntfrq_el0(uint32_t cntfrq_el0)
 {
 	__asm__ __volatile__("msr CNTFRQ_EL0, %0\n\t" : : "r" ((uint64_t)cntfrq_el0) : "memory");
 }
+
+uint64_t raw_read_cntpct_el0(void)
+{
+	uint64_t cntpct_el0;
+
+	__asm__ __volatile__("mrs %0, CNTPCT_EL0\n\t" : "=r" (cntpct_el0) : : "memory");
+	return cntpct_el0;
+}

src/arch/arm64/include/armv8/arch/lib_helpers.h

@@ -557,6 +557,7 @@ uint64_t raw_read_vbar(uint32_t el);
 void raw_write_vbar(uint64_t vbar, uint32_t el);
 uint32_t raw_read_cntfrq_el0(void);
 void raw_write_cntfrq_el0(uint32_t cntfrq_el0);
+uint64_t raw_read_cntpct_el0(void);
 
 /* Cache maintenance system instructions */
 void dccisw(uint64_t cisw);